libbb/xconnect.c - codeaurora/busybox - Gitiles

 /* vi: set sw=4 ts=4: */
 /*
  * Utility routines.
  *
  * Connect to host at port using address resolution from getaddrinfo
  *
  * Licensed under GPLv2, see file LICENSE in this tarball for details.
  */

 #include <sys/socket.h> /* netinet/in.h needs it */
 #include <netinet/in.h>
 #include <net/if.h>
 #include <sys/un.h>
 #include "libbb.h"

 void FAST_FUNC setsockopt_reuseaddr(int fd)
 {
 	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1));
 }
 int FAST_FUNC setsockopt_broadcast(int fd)
 {
 	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
 }
 int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
 {
 	int r;
 	struct ifreq ifr;
 	strncpy_IFNAMSIZ(ifr.ifr_name, iface);
 	/* NB: passing (iface, strlen(iface) + 1) does not work!
 	 * (maybe it works on _some_ kernels, but not on 2.6.26)
 	 * Actually, ifr_name is at offset 0, and in practice
 	 * just giving char[IFNAMSIZ] instead of struct ifreq works too.
 	 * But just in case it's not true on some obscure arch... */
 	r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
 	if (r)
 		bb_perror_msg("can't bind to interface %s", iface);
 	return r;
 }

 len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd)
 {
 	len_and_sockaddr lsa;
 	len_and_sockaddr *lsa_ptr;

 	lsa.len = LSA_SIZEOF_SA;
 	if (getsockname(fd, &lsa.u.sa, &lsa.len) != 0)
 		return NULL;

 	lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len);
 	if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */
 		lsa_ptr->len = lsa.len;
 		getsockname(fd, &lsa_ptr->u.sa, &lsa_ptr->len);
 	} else {
 		memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len);
 	}
 	return lsa_ptr;
 }

 void FAST_FUNC xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
 {
 	if (connect(s, s_addr, addrlen) < 0) {
 		if (ENABLE_FEATURE_CLEAN_UP)
 			close(s);
 		if (s_addr->sa_family == AF_INET)
 			bb_perror_msg_and_die("%s (%s)",
 				"can't connect to remote host",
 				inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
 		bb_perror_msg_and_die("can't connect to remote host");
 	}
 }

 /* Return port number for a service.
  * If "port" is a number use it as the port.
  * If "port" is a name it is looked up in /etc/services,
  * if it isnt found return default_port
  */
 unsigned FAST_FUNC bb_lookup_port(const char *port, const char *protocol, unsigned default_port)
 {
 	unsigned port_nr = default_port;
 	if (port) {
 		int old_errno;

 		/* Since this is a lib function, we're not allowed to reset errno to 0.
 		 * Doing so could break an app that is deferring checking of errno. */
 		old_errno = errno;
 		port_nr = bb_strtou(port, NULL, 10);
 		if (errno || port_nr > 65535) {
 			struct servent *tserv = getservbyname(port, protocol);
 			port_nr = default_port;
 			if (tserv)
 				port_nr = ntohs(tserv->s_port);
 		}
 		errno = old_errno;
 	}
 	return (uint16_t)port_nr;
 }


 /* "Old" networking API - only IPv4 */

 /*
 void FAST_FUNC bb_lookup_host(struct sockaddr_in *s_in, const char *host)
 {
 	struct hostent *he;

 	memset(s_in, 0, sizeof(struct sockaddr_in));
 	s_in->sin_family = AF_INET;
 	he = xgethostbyname(host);
 	memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
 }


 int FAST_FUNC xconnect_tcp_v4(struct sockaddr_in *s_addr)
 {
 	int s = xsocket(AF_INET, SOCK_STREAM, 0);
 	xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr));
 	return s;
 }
 */

 /* "New" networking API */


 int FAST_FUNC get_nport(const struct sockaddr *sa)
 {
 #if ENABLE_FEATURE_IPV6
 	if (sa->sa_family == AF_INET6) {
 		return ((struct sockaddr_in6*)sa)->sin6_port;
 	}
 #endif
 	if (sa->sa_family == AF_INET) {
 		return ((struct sockaddr_in*)sa)->sin_port;
 	}
 	/* What? UNIX socket? IPX?? :) */
 	return -1;
 }

 void FAST_FUNC set_nport(len_and_sockaddr *lsa, unsigned port)
 {
 #if ENABLE_FEATURE_IPV6
 	if (lsa->u.sa.sa_family == AF_INET6) {
 		lsa->u.sin6.sin6_port = port;
 		return;
 	}
 #endif
 	if (lsa->u.sa.sa_family == AF_INET) {
 		lsa->u.sin.sin_port = port;
 		return;
 	}
 	/* What? UNIX socket? IPX?? :) */
 }

 /* We hijack this constant to mean something else */
 /* It doesn't hurt because we will remove this bit anyway */
 #define DIE_ON_ERROR AI_CANONNAME

 /* host: "1.2.3.4[:port]", "www.google.com[:port]"
  * port: if neither of above specifies port # */
 static len_and_sockaddr* str2sockaddr(
 		const char *host, int port,
 IF_FEATURE_IPV6(sa_family_t af,)
 		int ai_flags)
 {
 	int rc;
 	len_and_sockaddr *r;
 	struct addrinfo *result = NULL;
 	struct addrinfo *used_res;
 	const char *org_host = host; /* only for error msg */
 	const char *cp;
 	struct addrinfo hint;

 	if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) {
 		struct sockaddr_un *sun;

 		r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
 		r->len = sizeof(struct sockaddr_un);
 		r->u.sa.sa_family = AF_UNIX;
 		sun = (struct sockaddr_un *)&r->u.sa;
 		safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path));
 		return r;
 	}

 	r = NULL;

 	/* Ugly parsing of host:addr */
 	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
 		/* Even uglier parsing of [xx]:nn */
 		host++;
 		cp = strchr(host, ']');
 		if (!cp || (cp[1] != ':' && cp[1] != '\0')) {
 			/* Malformed: must be [xx]:nn or [xx] */
 			bb_error_msg("bad address '%s'", org_host);
 			if (ai_flags & DIE_ON_ERROR)
 				xfunc_die();
 			return NULL;
 		}
 	} else {
 		cp = strrchr(host, ':');
 		if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
 			/* There is more than one ':' (e.g. "::1") */
 			cp = NULL; /* it's not a port spec */
 		}
 	}
 	if (cp) { /* points to ":" or "]:" */
 		int sz = cp - host + 1;

 		host = safe_strncpy(alloca(sz), host, sz);
 		if (ENABLE_FEATURE_IPV6 && *cp != ':') {
 			cp++; /* skip ']' */
 			if (*cp == '\0') /* [xx] without port */
 				goto skip;
 		}
 		cp++; /* skip ':' */
 		port = bb_strtou(cp, NULL, 10);
 		if (errno || (unsigned)port > 0xffff) {
 			bb_error_msg("bad port spec '%s'", org_host);
 			if (ai_flags & DIE_ON_ERROR)
 				xfunc_die();
 			return NULL;
 		}
  skip: ;
 	}

 	memset(&hint, 0 , sizeof(hint));
 #if !ENABLE_FEATURE_IPV6
 	hint.ai_family = AF_INET; /* do not try to find IPv6 */
 #else
 	hint.ai_family = af;
 #endif
 	/* Needed. Or else we will get each address thrice (or more)
 	 * for each possible socket type (tcp,udp,raw...): */
 	hint.ai_socktype = SOCK_STREAM;
 	hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
 	rc = getaddrinfo(host, NULL, &hint, &result);
 	if (rc || !result) {
 		bb_error_msg("bad address '%s'", org_host);
 		if (ai_flags & DIE_ON_ERROR)
 			xfunc_die();
 		goto ret;
 	}
 	used_res = result;
 #if ENABLE_FEATURE_PREFER_IPV4_ADDRESS
 	while (1) {
 		if (used_res->ai_family == AF_INET)
 			break;
 		used_res = used_res->ai_next;
 		if (!used_res) {
 			used_res = result;
 			break;
 		}
 	}
 #endif
 	r = xmalloc(offsetof(len_and_sockaddr, u.sa) + used_res->ai_addrlen);
 	r->len = used_res->ai_addrlen;
 	memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);
 	set_nport(r, htons(port));
  ret:
 	freeaddrinfo(result);
 	return r;
 }
 #if !ENABLE_FEATURE_IPV6
 #define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags)
 #endif

 #if ENABLE_FEATURE_IPV6
 len_and_sockaddr* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af)
 {
 	return str2sockaddr(host, port, af, 0);
 }

 len_and_sockaddr* FAST_FUNC xhost_and_af2sockaddr(const char *host, int port, sa_family_t af)
 {
 	return str2sockaddr(host, port, af, DIE_ON_ERROR);
 }
 #endif

 len_and_sockaddr* FAST_FUNC host2sockaddr(const char *host, int port)
 {
 	return str2sockaddr(host, port, AF_UNSPEC, 0);
 }

 len_and_sockaddr* FAST_FUNC xhost2sockaddr(const char *host, int port)
 {
 	return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR);
 }

 len_and_sockaddr* FAST_FUNC xdotted2sockaddr(const char *host, int port)
 {
 	return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR);
 }

 #undef xsocket_type
 int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type)
 {
 	IF_NOT_FEATURE_IPV6(enum { family = AF_INET };)
 	len_and_sockaddr *lsa;
 	int fd;
 	int len;

 #if ENABLE_FEATURE_IPV6
 	if (family == AF_UNSPEC) {
 		fd = socket(AF_INET6, sock_type, 0);
 		if (fd >= 0) {
 			family = AF_INET6;
 			goto done;
 		}
 		family = AF_INET;
 	}
 #endif
 	fd = xsocket(family, sock_type, 0);
 	len = sizeof(struct sockaddr_in);
 #if ENABLE_FEATURE_IPV6
 	if (family == AF_INET6) {
  done:
 		len = sizeof(struct sockaddr_in6);
 	}
 #endif
 	lsa = xzalloc(offsetof(len_and_sockaddr, u.sa) + len);
 	lsa->len = len;
 	lsa->u.sa.sa_family = family;
 	*lsap = lsa;
 	return fd;
 }

 int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap)
 {
 	return xsocket_type(lsap, IF_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM);
 }

 static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type)
 {
 	int fd;
 	len_and_sockaddr *lsa;

 	if (bindaddr && bindaddr[0]) {
 		lsa = xdotted2sockaddr(bindaddr, port);
 		/* user specified bind addr dictates family */
 		fd = xsocket(lsa->u.sa.sa_family, sock_type, 0);
 	} else {
 		fd = xsocket_type(&lsa, IF_FEATURE_IPV6(AF_UNSPEC,) sock_type);
 		set_nport(lsa, htons(port));
 	}
 	setsockopt_reuseaddr(fd);
 	xbind(fd, &lsa->u.sa, lsa->len);
 	free(lsa);
 	return fd;
 }

 int FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port)
 {
 	return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
 }

 int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port)
 {
 	return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM);
 }


 int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port)
 {
 	int fd;
 	len_and_sockaddr *lsa;

 	lsa = xhost2sockaddr(peer, port);
 	fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
 	setsockopt_reuseaddr(fd);
 	xconnect(fd, &lsa->u.sa, lsa->len);
 	free(lsa);
 	return fd;
 }

 int FAST_FUNC xconnect_stream(const len_and_sockaddr *lsa)
 {
 	int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
 	xconnect(fd, &lsa->u.sa, lsa->len);
 	return fd;
 }

 /* We hijack this constant to mean something else */
 /* It doesn't hurt because we will add this bit anyway */
 #define IGNORE_PORT NI_NUMERICSERV
 static char* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags)
 {
 	char host[128];
 	char serv[16];
 	int rc;
 	socklen_t salen;

 	if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) {
 		struct sockaddr_un *sun = (struct sockaddr_un *)sa;
 		return xasprintf("local:%.*s",
 				(int) sizeof(sun->sun_path),
 				sun->sun_path);
 	}

 	salen = LSA_SIZEOF_SA;
 #if ENABLE_FEATURE_IPV6
 	if (sa->sa_family == AF_INET)
 		salen = sizeof(struct sockaddr_in);
 	if (sa->sa_family == AF_INET6)
 		salen = sizeof(struct sockaddr_in6);
 #endif
 	rc = getnameinfo(sa, salen,
 			host, sizeof(host),
 	/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
 			serv, sizeof(serv),
 			/* do not resolve port# into service _name_ */
 			flags | NI_NUMERICSERV
 	);
 	if (rc)
 		return NULL;
 	if (flags & IGNORE_PORT)
 		return xstrdup(host);
 #if ENABLE_FEATURE_IPV6
 	if (sa->sa_family == AF_INET6) {
 		if (strchr(host, ':')) /* heh, it's not a resolved hostname */
 			return xasprintf("[%s]:%s", host, serv);
 		/*return xasprintf("%s:%s", host, serv);*/
 		/* - fall through instead */
 	}
 #endif
 	/* For now we don't support anything else, so it has to be INET */
 	/*if (sa->sa_family == AF_INET)*/
 		return xasprintf("%s:%s", host, serv);
 	/*return xstrdup(host);*/
 }

 char* FAST_FUNC xmalloc_sockaddr2host(const struct sockaddr *sa)
 {
 	return sockaddr2str(sa, 0);
 }

 char* FAST_FUNC xmalloc_sockaddr2host_noport(const struct sockaddr *sa)
 {
 	return sockaddr2str(sa, IGNORE_PORT);
 }

 char* FAST_FUNC xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa)
 {
 	return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT);
 }
 char* FAST_FUNC xmalloc_sockaddr2dotted(const struct sockaddr *sa)
 {
 	return sockaddr2str(sa, NI_NUMERICHOST);
 }

 char* FAST_FUNC xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa)
 {
 	return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT);
 }
	/* vi: set sw=4 ts=4: */
	/*
	* Utility routines.
	*
	* Connect to host at port using address resolution from getaddrinfo
	*
	* Licensed under GPLv2, see file LICENSE in this tarball for details.
	*/

	#include <sys/socket.h> /* netinet/in.h needs it */
	#include <netinet/in.h>
	#include <net/if.h>
	#include <sys/un.h>
	#include "libbb.h"

	void FAST_FUNC setsockopt_reuseaddr(int fd)
	{
	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1));
	}
	int FAST_FUNC setsockopt_broadcast(int fd)
	{
	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
	}
	int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
	{
	int r;
	struct ifreq ifr;
	strncpy_IFNAMSIZ(ifr.ifr_name, iface);
	/* NB: passing (iface, strlen(iface) + 1) does not work!
	* (maybe it works on _some_ kernels, but not on 2.6.26)
	* Actually, ifr_name is at offset 0, and in practice
	* just giving char[IFNAMSIZ] instead of struct ifreq works too.
	* But just in case it's not true on some obscure arch... */
	r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
	if (r)
	bb_perror_msg("can't bind to interface %s", iface);
	return r;
	}

	len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd)
	{
	len_and_sockaddr lsa;
	len_and_sockaddr *lsa_ptr;

	lsa.len = LSA_SIZEOF_SA;
	if (getsockname(fd, &lsa.u.sa, &lsa.len) != 0)
	return NULL;

	lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len);
	if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */
	lsa_ptr->len = lsa.len;
	getsockname(fd, &lsa_ptr->u.sa, &lsa_ptr->len);
	} else {
	memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len);
	}
	return lsa_ptr;
	}

	void FAST_FUNC xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
	{
	if (connect(s, s_addr, addrlen) < 0) {
	if (ENABLE_FEATURE_CLEAN_UP)
	close(s);
	if (s_addr->sa_family == AF_INET)
	bb_perror_msg_and_die("%s (%s)",
	"can't connect to remote host",
	inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
	bb_perror_msg_and_die("can't connect to remote host");
	}
	}

	/* Return port number for a service.
	* If "port" is a number use it as the port.
	* If "port" is a name it is looked up in /etc/services,
	* if it isnt found return default_port
	*/
	unsigned FAST_FUNC bb_lookup_port(const char port, const char protocol, unsigned default_port)
	{
	unsigned port_nr = default_port;
	if (port) {
	int old_errno;

	/* Since this is a lib function, we're not allowed to reset errno to 0.
	* Doing so could break an app that is deferring checking of errno. */
	old_errno = errno;
	port_nr = bb_strtou(port, NULL, 10);
	if (errno \|\| port_nr > 65535) {
	struct servent *tserv = getservbyname(port, protocol);
	port_nr = default_port;
	if (tserv)
	port_nr = ntohs(tserv->s_port);
	}
	errno = old_errno;
	}
	return (uint16_t)port_nr;
	}


	/* "Old" networking API - only IPv4 */

	/*
	void FAST_FUNC bb_lookup_host(struct sockaddr_in s_in, const char host)
	{
	struct hostent *he;

	memset(s_in, 0, sizeof(struct sockaddr_in));
	s_in->sin_family = AF_INET;
	he = xgethostbyname(host);
	memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
	}


	int FAST_FUNC xconnect_tcp_v4(struct sockaddr_in *s_addr)
	{
	int s = xsocket(AF_INET, SOCK_STREAM, 0);
	xconnect(s, (struct sockaddr) s_addr, sizeof(s_addr));
	return s;
	}
	*/

	/* "New" networking API */


	int FAST_FUNC get_nport(const struct sockaddr *sa)
	{
	#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET6) {
	return ((struct sockaddr_in6*)sa)->sin6_port;
	}
	#endif
	if (sa->sa_family == AF_INET) {
	return ((struct sockaddr_in*)sa)->sin_port;
	}
	/* What? UNIX socket? IPX?? :) */
	return -1;
	}

	void FAST_FUNC set_nport(len_and_sockaddr *lsa, unsigned port)
	{
	#if ENABLE_FEATURE_IPV6
	if (lsa->u.sa.sa_family == AF_INET6) {
	lsa->u.sin6.sin6_port = port;
	return;
	}
	#endif
	if (lsa->u.sa.sa_family == AF_INET) {
	lsa->u.sin.sin_port = port;
	return;
	}
	/* What? UNIX socket? IPX?? :) */
	}

	/* We hijack this constant to mean something else */
	/* It doesn't hurt because we will remove this bit anyway */
	#define DIE_ON_ERROR AI_CANONNAME

	/* host: "1.2.3.4[:port]", "www.google.com[:port]"
	* port: if neither of above specifies port # */
	static len_and_sockaddr* str2sockaddr(
	const char *host, int port,
	IF_FEATURE_IPV6(sa_family_t af,)
	int ai_flags)
	{
	int rc;
	len_and_sockaddr *r;
	struct addrinfo *result = NULL;
	struct addrinfo *used_res;
	const char org_host = host; / only for error msg */
	const char *cp;
	struct addrinfo hint;

	if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) {
	struct sockaddr_un *sun;

	r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
	r->len = sizeof(struct sockaddr_un);
	r->u.sa.sa_family = AF_UNIX;
	sun = (struct sockaddr_un *)&r->u.sa;
	safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path));
	return r;
	}

	r = NULL;

	/* Ugly parsing of host:addr */
	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
	/* Even uglier parsing of [xx]:nn */
	host++;
	cp = strchr(host, ']');
	if (!cp \|\| (cp[1] != ':' && cp[1] != '\0')) {
	/* Malformed: must be [xx]:nn or [xx] */
	bb_error_msg("bad address '%s'", org_host);
	if (ai_flags & DIE_ON_ERROR)
	xfunc_die();
	return NULL;
	}
	} else {
	cp = strrchr(host, ':');
	if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
	/* There is more than one ':' (e.g. "::1") */
	cp = NULL; /* it's not a port spec */
	}
	}
	if (cp) { /* points to ":" or "]:" */
	int sz = cp - host + 1;

	host = safe_strncpy(alloca(sz), host, sz);
	if (ENABLE_FEATURE_IPV6 && *cp != ':') {
	cp++; /* skip ']' */
	if (cp == '\0') / [xx] without port */
	goto skip;
	}
	cp++; /* skip ':' */
	port = bb_strtou(cp, NULL, 10);
	if (errno \|\| (unsigned)port > 0xffff) {
	bb_error_msg("bad port spec '%s'", org_host);
	if (ai_flags & DIE_ON_ERROR)
	xfunc_die();
	return NULL;
	}
	skip: ;
	}

	memset(&hint, 0 , sizeof(hint));
	#if !ENABLE_FEATURE_IPV6
	hint.ai_family = AF_INET; /* do not try to find IPv6 */
	#else
	hint.ai_family = af;
	#endif
	/* Needed. Or else we will get each address thrice (or more)
	* for each possible socket type (tcp,udp,raw...): */
	hint.ai_socktype = SOCK_STREAM;
	hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
	rc = getaddrinfo(host, NULL, &hint, &result);
	if (rc \|\| !result) {
	bb_error_msg("bad address '%s'", org_host);
	if (ai_flags & DIE_ON_ERROR)
	xfunc_die();
	goto ret;
	}
	used_res = result;
	#if ENABLE_FEATURE_PREFER_IPV4_ADDRESS
	while (1) {
	if (used_res->ai_family == AF_INET)
	break;
	used_res = used_res->ai_next;
	if (!used_res) {
	used_res = result;
	break;
	}
	}
	#endif
	r = xmalloc(offsetof(len_and_sockaddr, u.sa) + used_res->ai_addrlen);
	r->len = used_res->ai_addrlen;
	memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);
	set_nport(r, htons(port));
	ret:
	freeaddrinfo(result);
	return r;
	}
	#if !ENABLE_FEATURE_IPV6
	#define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags)
	#endif

	#if ENABLE_FEATURE_IPV6
	len_and_sockaddr* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af)
	{
	return str2sockaddr(host, port, af, 0);
	}

	len_and_sockaddr* FAST_FUNC xhost_and_af2sockaddr(const char *host, int port, sa_family_t af)
	{
	return str2sockaddr(host, port, af, DIE_ON_ERROR);
	}
	#endif

	len_and_sockaddr* FAST_FUNC host2sockaddr(const char *host, int port)
	{
	return str2sockaddr(host, port, AF_UNSPEC, 0);
	}

	len_and_sockaddr* FAST_FUNC xhost2sockaddr(const char *host, int port)
	{
	return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR);
	}

	len_and_sockaddr* FAST_FUNC xdotted2sockaddr(const char *host, int port)
	{
	return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST \| DIE_ON_ERROR);
	}

	#undef xsocket_type
	int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type)
	{
	IF_NOT_FEATURE_IPV6(enum { family = AF_INET };)
	len_and_sockaddr *lsa;
	int fd;
	int len;

	#if ENABLE_FEATURE_IPV6
	if (family == AF_UNSPEC) {
	fd = socket(AF_INET6, sock_type, 0);
	if (fd >= 0) {
	family = AF_INET6;
	goto done;
	}
	family = AF_INET;
	}
	#endif
	fd = xsocket(family, sock_type, 0);
	len = sizeof(struct sockaddr_in);
	#if ENABLE_FEATURE_IPV6
	if (family == AF_INET6) {
	done:
	len = sizeof(struct sockaddr_in6);
	}
	#endif
	lsa = xzalloc(offsetof(len_and_sockaddr, u.sa) + len);
	lsa->len = len;
	lsa->u.sa.sa_family = family;
	*lsap = lsa;
	return fd;
	}

	int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap)
	{
	return xsocket_type(lsap, IF_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM);
	}

	static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type)
	{
	int fd;
	len_and_sockaddr *lsa;

	if (bindaddr && bindaddr[0]) {
	lsa = xdotted2sockaddr(bindaddr, port);
	/* user specified bind addr dictates family */
	fd = xsocket(lsa->u.sa.sa_family, sock_type, 0);
	} else {
	fd = xsocket_type(&lsa, IF_FEATURE_IPV6(AF_UNSPEC,) sock_type);
	set_nport(lsa, htons(port));
	}
	setsockopt_reuseaddr(fd);
	xbind(fd, &lsa->u.sa, lsa->len);
	free(lsa);
	return fd;
	}

	int FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port)
	{
	return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
	}

	int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port)
	{
	return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM);
	}


	int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port)
	{
	int fd;
	len_and_sockaddr *lsa;

	lsa = xhost2sockaddr(peer, port);
	fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
	setsockopt_reuseaddr(fd);
	xconnect(fd, &lsa->u.sa, lsa->len);
	free(lsa);
	return fd;
	}

	int FAST_FUNC xconnect_stream(const len_and_sockaddr *lsa)
	{
	int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
	xconnect(fd, &lsa->u.sa, lsa->len);
	return fd;
	}

	/* We hijack this constant to mean something else */
	/* It doesn't hurt because we will add this bit anyway */
	#define IGNORE_PORT NI_NUMERICSERV
	static char* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags)
	{
	char host[128];
	char serv[16];
	int rc;
	socklen_t salen;

	if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) {
	struct sockaddr_un sun = (struct sockaddr_un )sa;
	return xasprintf("local:%.*s",
	(int) sizeof(sun->sun_path),
	sun->sun_path);
	}

	salen = LSA_SIZEOF_SA;
	#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET)
	salen = sizeof(struct sockaddr_in);
	if (sa->sa_family == AF_INET6)
	salen = sizeof(struct sockaddr_in6);
	#endif
	rc = getnameinfo(sa, salen,
	host, sizeof(host),
	/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
	serv, sizeof(serv),
	/* do not resolve port# into service _name_ */
	flags \| NI_NUMERICSERV
	);
	if (rc)
	return NULL;
	if (flags & IGNORE_PORT)
	return xstrdup(host);
	#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET6) {
	if (strchr(host, ':')) /* heh, it's not a resolved hostname */
	return xasprintf("[%s]:%s", host, serv);
	/return xasprintf("%s:%s", host, serv);/
	/* - fall through instead */
	}
	#endif
	/* For now we don't support anything else, so it has to be INET */
	/if (sa->sa_family == AF_INET)/
	return xasprintf("%s:%s", host, serv);
	/return xstrdup(host);/
	}

	char* FAST_FUNC xmalloc_sockaddr2host(const struct sockaddr *sa)
	{
	return sockaddr2str(sa, 0);
	}

	char* FAST_FUNC xmalloc_sockaddr2host_noport(const struct sockaddr *sa)
	{
	return sockaddr2str(sa, IGNORE_PORT);
	}

	char* FAST_FUNC xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa)
	{
	return sockaddr2str(sa, NI_NAMEREQD \| IGNORE_PORT);
	}
	char* FAST_FUNC xmalloc_sockaddr2dotted(const struct sockaddr *sa)
	{
	return sockaddr2str(sa, NI_NUMERICHOST);
	}

	char* FAST_FUNC xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa)
	{
	return sockaddr2str(sa, NI_NUMERICHOST \| IGNORE_PORT);
	}